With the increasing concern for safety, there is a positive move toward providing safe materials for public and household use. One particular area of need is that of providing flame resistant or flame retardant products for use by the ultimate consumer. As a result of this demand, many products are being required to meet certain flame retardant criteria both by local and federal government and the manufacturers of such products. One particular set of conditions employed as a measuring standard for flame retardancy is set forth in Underwriters' Laboratories, Inc. Subject 94. This document sets forth certain conditions by which materials are rated.
In the art, there are many known flame retardant additives which are employed by mixing with products to render such materials flame retardant. Such flame retardant additives have been known to be employed in amounts of 5 to 20 weight percent in order to provide flame retardant characteristics to those products which are combustible.
Aromatic carbonate polymer compounds (polyarylenecarbonates), polyarylsulfones, and polyarylethersulfones, in admixture with themselves, or when blended with acrylonitrile-butadiene-styrene copolymer (ABS), do not exhibit adequate flame retardancy to meet Underwriters' Laboratories Subject 94 ratings in certain thicknesses. As a result, various flame retardant additives have been disclosed in the art which render such compositions flame retardant, which are effective in varying degrees.
Furthermore, when used alone the aforementioned aromatic carbonate polymer compounds (polarylene-carbonates) polyarylsulfones and polyarylethersulfones, while sometimes meeting the broad standard of Underwriters' Laboratories Subject, nevertheless exhibit longer flame out times than when used in admixture with the compounds which are the subject of the present invention.